Daniel Duncan

Daniel Duncan, Dan Duncan, or Danny Duncan may refer to:
 * Daniel Duncan (physician) (1649–1735), Scottish-French doctor and chemist
 * Daniel Duncan (Ohio politician) (1806–1849), congressman from the US state of Ohio
 * Daniel Duncan McKenzie (1859–1927), parliamentarian and jurist from the Canadian province of Nova Scotia
 * Daniel Kablan Duncan (born 1943), foreign minister of Côte d'Ivoire
 * Dan Duncan (1933–2010), American co-founder, chairman and majority shareholder of Enterprise Products
 * Danny Duncan (musician) (born 1986), musician with We the Kings